As far as I know linux is (as most OS) writing to the SD Card from time to time.
The Writing operation to SD Cards is limited.
I belive it can be changed so there is no writing to the SD card.
Something like “sudo swapoff -a”
To make a long strory short:
Does volumio swap?
Can swapping be disabled?
I could try but my last experiments (plural!!!) mostly ended up with
writing the image back to the card.
thanks